Short tip for the blank screen on 8.1 upgrade ( happens when you're too lazy to uninstall graphic drivers ) : if you didn't add the safe mode option and you still want to get into safe mode the easy way ( frustrating anyway) is to hold the Shift key while pressing like a maniac F8 key before turn on the machine. If you get the spinning dots, in that moment turn off your machine and restart the procedure. Be fast! If you cannot enter in safe mode and if you have a second machine than grab the hdd/ssd and manually delete the graphic driver. Once you are back do a regedit clean HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\servic es. Live CD, Knoppix also helps, if you don't have recovery media dvds. I'll be ba ck with all the steps required. Now i'm in the process of fixing it on my HP notebook.